keeping in mind that it is only valid for contributions that
have an \(s\) -channel cut.
We apply
IBP identities [1]} in \(4-2\epsilon \) 
dimensions to reduce the above integrals to the master integrals in
Eq. (REF ), using the
software FIRE6 [2]}. Upon reducing to master
integrals we remove the ones that have no \(s\) -channel cut.
